Control of fluid flow through various parts of a wellbore is important for optimizing production. Valves to control fluid flow have been developed and are widely used. In some situations it is sufficient to use a valve with only two settings, fully open and fully closed. In other situations it is desirable to be able to choke the flow without shutting it off completely. As wells become more sophisticated there is a desire for increasing accuracy in flow control.
The increasing sophistication of wells also includes an increase in operating costs and consequently an increase in cost for time in which a well is not producing. Failure of flow control valves is, therefore, a costly and undesirable condition. Accordingly, the art is in need of highly durable flow control valves that have highly accurate flow control.